Dr. S. D. Rajan
Due: 11 am Oct 16,
Arizona State University
2014
CEE321 Structural Analysis & Design
Design Project 1
This is a team project. Please ask for clarifications by posting your questions on the
Discussion Board. You are required to use the GS-USA© software for carrying out the
design. Changes may be made to the following specifications and any updated versions
of this document will be posted on the class web site. Check the Discussion Board and
the Assignment web pages periodically for updated information.
1. Problem Statement
Design a 10-storied office building with a rectangular footprint, located in downtown
Tempe. The building is to be modeled as a planar steel frame with rigid connections.
ASCE 7-2010 design code requirements must be used for computing dead, live and wind
loads. A typical floor plan is shown in Fig. 1.
A
B
C
D
E
F
G
x
s
s
s
s
s
s
s
x1
x1
x2
x2
x3
x3
6@s ft=6s ft
z
Fig. 1 Typical floor plan (x-z plane; y: gravity direction)
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The planar frame that is to be designed is the shaded frame shown in Fig. 1. Note that s
is the spacing between the frames.
2. Design Objective
Minimize the cost of the structure, while satisfying all of the specifications listed below.
3. Building Configuration
a. Take the total span of the typical frame as 120 ft, i.e. 6s = 120 ft.
b. All connections are rigid connections.
c. The height of the first floor containing the lobby is 16 ft. All the other floor
heights are 13 ft.
d. The floor system consists of 3” cellular steel deck with 2.5” concrete slab
supported on the steel joists.
e. Make sure that your model can be analyzed by the GS-USA Frame© program.
GS-USA supports a maximum of 150 members and 50 design variables.
f. Take the total number of frames in the z-direction as 15.
g. All supports must be modeled as fixed supports.
h. The spacing between adjacent columns cannot be less than 10 ft (note that
this effects the values of x1 and x2).
i. The building will primarily be leased by firms specializing in cloud computing
with some space in some floors used for dining areas and restaurants.
j. The roof is not earmarked for any special use.
k. An example layout of the typical planar frame is shown in Fig. 2.
6@20’=120 ft
133 ft
y
x
Fig. 2 Typical building frame
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4. Member Properties
a. Materials: The steel columns, beams and bracings of the building are
assumed to be of grade A992/A992M. The floor slabs are assumed to be of
high strength reinforced concrete.
Material
Table 1. Material Properties
Structural element
Material Property
Steel, Grade Columns, beams, and
A992/A992M bracings
Concrete
Slab
Value
Mass density
7.47 104 
Elastic Modulus
2.9 104  ksi
Yield stress
50000 psi
Mass density
2.25 104 
Poisson’s Ratio
0.15
Elastic Modulus
4.6 103  ksi
slugs
in3
slugs
in3
b. Cross-Sections: The members of the structure are custom-made wide flange
sections. With web height, hw , flange width, w f , web thickness, t w , and
flange thickness, t f , the relationships between the four cross-sectional
dimensions can be established as (units are inches)
w f  0.235hw  7.12
(1)
t f  0.492tw  0.106
(2)
t f  0.0406w f  0.118
(3)
It is recommended that you take the web height as the design variable for
each different cross-section. The web and flange thicknesses cannot be less
than 0.25 in.
c. You may group the members appropriately in order to reduce the number of
different cross sections and must justify how and why the grouping decision
was taken.
5. Loads
The building must be capable of safely carrying the following loads:
a. Dead Loads:
i. Weight of the cellular steel deck and reinforced concrete floor slab.
ii. Self-weight of structure materials.
iii. Ignore the weight of the transverse beams.
iv. Use ASCE 7-2010.
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b. Live Loads:
i. Use ASCE 7-2010.
6. Loads and Load Combinations
In Allowable Stress Design, the combinations of service loads are evaluated for
maximum stresses and compared to allowable stresses. ASCE-7-2010 combinations of
loads that must be used in the design project, are shown below.
1. LC 1: Dead load
2. LC 2: Dead load + Live load
3. LC 3: Dead load + 0.6 Wind Load
4. LC 4: Dead load + 0.75 Live Load + 0.75(0.6 Wind Load)
7. Structural Safety
The building will comply with the following structural requirements ( f y is the yield
stress of steel).
a. Tensile stress cannot exceed 0.6 f y .
b. Compressive stress cannot exceed 0.6 f y .
c. Shear stress cannot exceed 0.4 f y .
d. Euler buckling must be satisfied with a safety factor 2.0.
e. Horizontal deflection cannot exceed H/500 where H is the total height of the
building.
8. Cost
The cost of the design will be calculated using the following cost factors:
a. Material Cost: $0.50 per kilogram.
b. Connection Cost: $500 + $20 x m (# of members at joint) per joint.
c. Product Cost: $500 per product (this is not per element)
i. In real structural design and construction, the most economical design is
often not the one that simply minimizes the material cost. Often
standardizing the materials and member sizes can reduce the total cost
of the structure. If all the members in a structure are different materials
and sizes, then the cost of ordering, fabricating, and constructing those
members will be relatively high. If many members are the same,
fabrication and construction costs will be relatively lower.
ii. If the structure uses only one cross sectional area then the product cost is
$500 for the entire structure. If the structure uses only two different
types of cross sectional areas then the product cost is $1000 for the
entire structure. This accommodates for additional manufacturing
expenses. Further penalties and expenses would be expected if more
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than one steel material is used, however this problem clearly defines that
only one steel material is to be used.
NOTE: Multiply the final calculations in parts a, b, and c by 15, which is the
total number of planar frames in the building.
Report the final cost calculations using the style shown in Table 2. Adjust the style and
contents, if necessary, for your particular design.
Item
Material cost
Connection cost
Table 2. Summary of Final Cost Calculations
Quantity per frame Unit cost
Product cost
TOTAL BUILDING COST
15
SUM
$mno/frame
Cost per frame
$abc
$def
$ghi
$mno
$PQR=(15)(mno)
9. Report Format
(1) Title Page.
(2) Table of Contents.
(3) Group Work Log. This should contain a sufficiently detailed log of your group as well
as individual activities – who did what, when and about how long. If and when there are
problems with a group, it is the responsibility of each individual to bring this to my
attention as quickly as possible.
(4) Design Problem Statement.
(5) Problem Data and Assumptions (including limitations)
(i) With respect to structural analysis.
(ii) With respect to design requirements.
(iii) Tools used for analysis and design.
Make a checklist of all the different checks that needs to be made to ensure that the
design is a valid design.
(6) Initial Design. Explain your choice of initial design. Show what you checked by hand
to ensure that the initial design made sense.
(7) Details of Design Iterations. Explain your strategy in making the design changes.
(8) Final Design. The final design must be checked against GS-USA computer output. The
final design results must also be checked by hand.
(9) Turn in an electronic version as a MS Word file. In a zip file put in all the GS-USA files.
Create subdirectories called Initial Design, Intermediate Designs, and Final Design. The
subdirectories Initial Design and Final Design should have one and only one GS-USA file
corresponding to the initial and final design, respectively. e-mail the electronic files to
the TA.
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Requirements
(i) The Group Work Log must be signed by all members of the group.
(ii) Draw legible figures. Relevant figures must be drawn using AUTOCAD.
(iii) Use tables to represent information.
(iv) Must show all hand calculations, computer program listings, and computer program
output, whenever applicable.
(v) The analysis of the initial and final designs must be done using GS-USA© program.
There is no requirement that you use the design features of the GS-USA© program.
However, the initial and final designs must be analyzed and checked by the GS-USA©
program.
(vi) Send me via e-mail, peer assessment (of the other members in your group) within 24
hours of turning in your group report.
Grading Procedure
(i) Report ...................................................................................................................25%
(ii) Choice of tools and procedures used ...................................................................15%
(iii) Assumptions are reasonable and design meets requirements ...........................40%
(iii) Scaled score with respect to the best design ......................................................20%
(iv) Bonus points will be given for generating the model using a MATLAB code. Please
see me for details.
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